239 results about "Exposure compensation" patented technology

The present invention provides an image processing method. In one embodiment, the method provides discontinuity-preserving image smoothing and segmentation, noise reduction, reduction of image variations particularly those variations caused by illumination conditions, exposure compensation, and dynamic range compression. The present invention also provides an electronic image sensor that is able to detect high dynamic range optical images and produce electronic images with reduced dynamic range.

The present invention is to provide a method for enabling an electronic device to read at least two images taken from different positions by a digital camera mounted with a fisheye lens; acquire internal and external parameters of the fisheye lens corresponding to the different positions as well as the vignetting coefficient for eliminating the vignetting on the images; perform exposure compensation and color calibration on the images for letting them have consistent brightness and hues; project the images onto a spherical surface and spread out the spherical surface to form a two-dimensional spread-out picture based on the parameters; register the overlapped images projected on the two-dimensional spread-out picture and adjust the offset of corresponding pixels thereof, register and adjust the brightness and hues of the overlapped images into consistency; and fuse overlapped images together to produce a 360-degree spherical panorama without having any noticeable stitching seam between the images.

The invention discloses a method for exposing and compensating digital images, comprising the steps as follows: digital images are divided into a plurality of regions; the gain value of the region is determined according to the average brightness value of each region; according to the gain value of the region, the pixels of the digital images are exposed and compensated. The invention also discloses a device for exposing and compensating the digital images. The proposal of the invention can darken the bright area in the digital images, brighten the dark area in the digital image and can remain the details in the images as much as possible.

Retasking of one or more photographic exposure controls of a camera to give direct manual control of a power output level of a lighting device by mapping a dynamic range of a photographic exposure compensation control of the camera to a dynamic range of a power output level of the lighting device. In another example, mapping is used in automatic tracking of changes in ISO and/or aperture of a camera to a power output level of a lighting device. In one example, automatic tracking of power control can be provided to lighting devices (such as studio strobes) that do not usually have access to automated power control from a camera.

An automatic exposure control method and compensation apparatus are disclosed. It includes a coordinate system having sub-ranges with different corresponding exposure compensation values. It includes the setting of bright and dark regions threshold values and the calculation of the ratios of the pixel count in an image where the luminance of each pixel is higher than the bright area threshold value for obtaining a bright area ratio, and also includes the calculation of the ratio of the pixel count in an image where the luminance of each pixel is lower than the dark area threshold value for obtaining a dark area ratio. Afterwards, the image position in the coordinate system is determined. When the image position in the coordinate system is fallen inside one of the sub-ranges, the corresponding exposure compensation value of the sub-range where the image is located is given to compensate the exposure value of the image.

The invention discloses a camera automatic exposure method, a device, a camera device and a mobile terminal, and relates to the digital photographing technology. The method comprises the steps of determining the current exposure value of a camera on the basis of a camera response curve according to the brightness value of a photograph, wherein the camera response curve is a corresponding relation between the exposure value of the camera and the photograph brightness; determining the exposure compensation amount according to the current exposure value and the optimal exposure value of the camera, and determining the optimal exposure value according to the camera response curve; adjusting the camera so as to adjust the brightness of a photograph pixel according to the exposure compensation amount. On the basis of the inherent response curve of the camera, the current exposure value corresponding to the photograph brightness is obtained, the exposure compensation amount of the current exposure value and the exposure compensation amount of the optimal exposure value are obtained, the brightness of the photograph pixel is adjusted according to the exposure compensation amount, the automatic exposure adjustment is carried out on the basis of the camera inherent response curve and is not carried out on the basis of the brightness value of the taken photograph in the prior art, and the camera automatic exposure method has the advantages of being more accurate, more stable and higher in adaptability.

The invention discloses an image stitching method and device. The image stitching method and device are suitable for a binocular vision mobile robot platform, images collected through two eyes of a robot are stitched through an image stitching technology, the view of the robot can be increased, and the robot can better finish locating and environment reestablishment conveniently. The method includes the steps that image sequence feature points are extracted through an SUPF feature to form a feature vector; the feature vector space is searched, and feature matching points are searched; model parameters are estimated and converted robustly through a random sample consensus (RANSAC) algorithm; coordinate conversion is conducted on the images to be matched through a conversion mode, and the coordinate unification of the image sequence is achieved; the conversion relation met by the image sequence brightness space is estimated according to the brightness value of the corresponding matching points to achieve exposure compensation; the image overlapping region pixel value is determined through a pixel label method, and ghost reduction of the stitched images is achieved; image masks are generated according to the optimal label value set, and Laplacian pyramid fusion is conducted on the images.

The invention discloses a method and device for obtaining the exposure compensation value of a high-dynamic-range image, wherein the method comprises the steps of: determining various-colour channel histograms corresponding to a current scene, wherein the various-colour channel histograms include the corresponding relationship of different brightness and pixel scales under various-colour channels;according to a pre-set normal exposure brightness threshold value and pixel scale threshold value and the corresponding relationship of different brightness and pixel scales under various-colour channels, determining the underexposure degree and overexpose degree of the current scene; and, according to the underexposure degree and overexpose degree of the current scene, determining the underexposure compensation value and the overexpose compensation value of the current scene. By means of the method disclosed by the invention, the exposure compensation amount of a shot image can be adaptivelydetermined according to different shooting scenes, so that optimal dynamic exposure compensation on the shot image can be realized; therefore, the quality of the shot image is good; and the user experience is improved.

The invention discloses a figure photographing method and device and image pickup equipment. The method includes: when detecting that a current shooting scene is a backlighting scene, extracting a figure part in the current shooting scene based on depth of field information of the current shooting scene; obtaining first exposure compensation of the figure part, and shooting the current shooting scene according to the first exposure compensation to obtain a first image; extracting a background part in the current shooting scene; obtaining second exposure compensation of the background part, and shooting the current shooting scene according to the second exposure compensation to obtain a second image; and performing fusion processing on the first image and the second image, so as to obtain a fused target image. The figure photographing method provided by the embodiment of the invention achieves the purpose of automatic exposure of a backlighting figure based on multiframe fusion, and can enable the figure and background part in the shot image that is finally obtained to realize reasonable exposure, thereby realizing a better visual effect, and improving user experience.

The invention discloses an image exposure compensation method and device, and a computer-readable storage medium. The image exposure compensation method may comprise the following steps: in an image shooting process, according to pixel distribution characteristics of a shot preview image, dividing the shot preview image into a plurality of exposure compensation subareas; according to pixel distribution characteristics of each of the exposure compensation subareas, obtaining exposure compensation parameters corresponding to the each of the exposure compensation subareas; and according to the exposure compensation parameters corresponding to the exposure compensation subareas, respectively performing exposure compensation on the exposure compensation parameters. Compared with the image local exposure compensation in the prior art, according to the image exposure compensation method and device, and the computer-readable storage medium, the division of the exposure compensation subareas is performed on the image according to the pixel distribution characteristics of the image, and the each of the subareas is provided with the corresponding exposure compensation parameters, so the each of the exposure compensation subareas may obtain appropriate exposure compensation at different degrees; the possibilities for occurrence of overexposure and underexposure are effectively reduced, the outline and the stereoscopic impression of the image are reinforced, the imaging quality of the image is improved, and the shooting experience of a user is improved.

The invention relates to a method for automatic exposure compensation of backlit scenes in a video imaging system. The method includes the steps: a, acquiring required images, inputting the images into an image statistic device, and outputting a brightness average value Yave, a brightness deviation Ystd and an underexposure pixel percentage Punder after statistics of the image statistic device; b, computing to obtain a judgment reference value Yref satisfying the equation that Yref=Ystd/Yave, and comparing the judgment reference value Yref with a preset upper threshold and a preset lower threshold so as to judge scene states of the acquired images of an image acquirer; and c, when the acquired images of the image acquirer are backlit scenes, computing exposure target values of the images according to the underexposure pixel percentage Punder, performing exposure compensation for the images according to the exposure target values and enabling the image acquirer to perform normal scene exposure image acquisition under the exposure target values, and otherwise, enabling the image acquirer to perform normal scene image acquisition. The method is simple and convenient to operate, capable of improving effectiveness and stability of exposure compensation and wide in application range.

The invention belongs to the technical field of image exposure, and relates to an automatic exposure control method. The automatic exposure control method comprises the steps of S1, carrying out imagecollected by using binocular vision and an active structural light source projection method, and obtaining the last image collected each time; S2, obtaining the average brightness of the image by using a dynamic partitioning and dynamic weight coefficient adjusting method; S3, judging whether the average brightness of the image is within a target brightness range or not, if so, not carrying out exposure compensation and terminating the automatic exposure control, otherwise, entering the step S4; and S4, obtaining the difference between the average brightness of the image and the target brightness, selecting the corresponding step size for exposure compensation according to the difference and returning back to the step S1. The automatic exposure control method soles the problems of great noise signal, insufficient or excessive exposure of a target area due to excessive contrast between the target object and the background, excessively long adjustment time and excessively great difference between the image brightness and the target brightness in the prior art.

Disclosed is a color night vision system including a single-4-color image sensor configured to acquire a red, green, blue (RGB) image and an infrared (IR) image by processing RGB light signals and an IR light signal for each wavelength; and a processor configured to determine an exposure state of the RGB image by analyzing a brightness distribution of the RGB image, to decide at least one of an exposure compensation level of the RGB image, a denoising level of the RGB image, or a synthesis ratio between the RGB image and the IR image based on the determination result, and to create an output image based on the decision result that is made using the RGB image and the IR image.

The embodiment of the invention discloses an information processing method and an electronic device. The electronic device is used for determining an image brightness difference value of a first image and a second image at an image stitching part; if the image brightness difference value meets a first preset condition, determining a first image region of the first image at the image stitching part, and determining a second image region of the second image at the image stitching part; and based on the brightness of the first image region and the brightness of the second image region, respectively performing exposure compensation for the first image and the second image.

The invention discloses a mine multi-camera video fusion method based on GPU and CPU cooperative computing and belongs to the mine multi-camera video fusion method. The method is characterized in that a GPU and CPU cooperative computing model is established, and thus current situation of poor real-time performance of an existing video fusion method is relieved; automatic matching is carried out by utilizing features of overlapped regions between adjacent video sources to determine relative position relation of the video sources, so that positions of cameras do not need to be assigned in advance, and automatic integration is realized; camera parameter bundle adjustment estimation and automatic alignment are carried out, so that the problem of deformation of panorama images after fusion is solved; and an exposure compensation and multiband fusion method is adopted, and finally, an ultrahigh-resolution large-visual angle mine mining (extraction) working face large-scale scene real-time integral video is generated, so that the method plays an important role for improving coal mining work efficiency and guaranteeing coal mine safety production. The advantages are that the multi-camera video fusion method utilizes the existing cameras of a coal mine fully to generate the mine mining (extraction) working face panorama video, thereby reducing equipment investment and improving safety of coal mine production.

A method for simulating dark-part exposure compensation of high dynamic range images using a single image includes steps of: performing bright-part-enhancing image processing and saturation-contrast-enhancing image processing to obtain images P1, P2, respectively; selecting one of the images P1, P2; performing bright and dark parts identifying image processing on a selected image; performing blurring image processing on the selected image, to obtain a weight-reference image P3; and performing mixed weight calculation on pixels of the image P1 and pixels of the image P2 according to weights of pixels of the weight-reference image P3, respectively, so as to mix the image P1 and the image P2 to obtain a mixed image P4, wherein the pixels of the images P1, P2 on which the mixed weight calculation is performed correspond to the pixels of the weight-reference image P3, respectively. Hence, excessively dark parts typical of an image of undesirably high contrast are improved by reference to a single.

The present invention describes techniques for dynamic automatic exposure compensation within image capture devices. The techniques include dynamically adjusting a default target brightness for a scene to compensate an exposure value (EV) selected by an automatic exposure process. A sensor array obtains light information from the scene at a default target brightness and an image capture controller calculates brightness values of a plurality of regions in the scene based on the light information. An automatic exposure compensation module dynamically adjusts the default target brightness based on the brightness values for the plurality of regions in the scene and threshold values set for the sensor array to set an adjusted target brightness. The sensor array may then capture an image frame of the scene using an EV for the adjusted target brightness. The techniques also include building a hysteresis zone to substantially stabilize the adjusted target brightness over a sequence of image scenes.

The invention discloses a high dynamic range imaging optimization method and a device, which aim at increasing the brightness of insufficient exposure parts in a high dynamic range. In the invention, single-frame colorful images are used as a foundation; the information of other pixels in a certain scope surrounding a single pixel is used to implement accuracy judgment on whether the pixel exposure is sufficient or not; then the image is converted into a linear space; exposure compensation is implemented on the pixels with insufficient exposure to improve the brightness of the pixels with insufficient exposure and avoid color distortion possibly caused by directly improving the pixel values or possibly formed false details; besides, the whole treatment process is simple to operate and has low complexity. The invention is particularly suitable for being implemented on small devices with limited operation processing capacity like mobile phones, digital cameras, etc.

The invention discloses a real time panorama tracing and splicing method for mobile platform. First, each image frame captured by a camera is used for feature tracking and is then utilized for calculating rotation posture of the camera in three-dimensional space. Second, whether the center of the camera shifts or not is also detected during the process of estimating the posture of the camera in real time. If shift occurs, a corresponding feedback is sent to a user and help is offered to the user to reset the camera position to an initial one, so that translation error between captured images can be reduced and that the images meets constraint on a sphere is guaranteed. Third, key frames and three-dimensional feature points are added and related parameters are optimized and a Map is updated completely by utilizing a bundling adjustment method. Fourth, a plurality of pictures are spliced together in real time in an offline manner on a background, and exposure compensation and multi-frequency-band fusion of images are realized, so that a panorama with geometrical consistency is generated with high quality. The result indicates that a scene expression method based on multi-view panorama has very good scene expression capability.

The invention discloses a mobile terminal with an automatic exposure compensation function and an automatic exposure compensation method. The automatic exposure compensation method comprises the following steps of: acquiring the environment brightness, carrying out analog-digital conversion on the environment brightness and storing the converted environment brightness into a buffer module; and extracting environment brightness data in the buffer module, searching a corresponding relation of the environment brightness and an exposure compensation value according to the environment brightness, outputting the corresponding exposure compensation value and carrying out automatic exposure according to an original exposure parameter. According to the invention, in the shooting process, the corresponding exposure compensation value is searched according to the environment brightness and is overlapped on the original exposure parameter to carry out automatic exposure; and the exposure compensation mode has small regulating range and simple implementing process. Moreover, on the premise of not increasing the hardware cost of the mobile terminal, the shooting effect of the mobile terminal is improved and the competitiveness of the mobile terminal in the market is improved.

The method comprises: building a coordinator domain corresponding to multi steps of exposure compensation, and setting threshold values for bright area and dark area; calculating ratio of the amount of pixels whose brightness are more than the threshold value of bright area to the total amount of pixels in order to get the ratio value of bright area; calculating the ratio of the amount of pixels whose brightness are less than the threshold value of dark area to the total amount of pixels in order to get the ratio value of dark area; according to the ratio value of bright area and the ratio value of dark area, determining the location of image in the coordinator domain; according to the steps of coordinator domain where the image locates at, compensating the exposure to the image.